GSE: a great discovery!

One morning in France Jacob Harich was enjoying the taste of a grapefruit for breakfast. World War II had just ended and since fresh fruit was a rare treat in Europe at that time, Harich was appreciating the special delight all the more – until, that is, he bit into a seed! The extremely bitter taste of the seed somehow broke the spell but also prompted him to wonder about what it was that made the seed so bitter. For most people, the question would have been of mere passing interest, but for Harich, a budding scientist, it inspired a compelling inquiry…

Jacob Harich was born in Yugoslavia in 1919 and educated in Germany. After witnessing the horrors of war as a fighter pilot, he was inspired to devote the rest of his life to improving the human condition.  He continued to study medicine for the rest of his life, specializing in gynaecology and immunology. After moving to the United States in 1957, Dr Harich engaged in further studies at Long Island University, N.Y. But it wasn’t until 1963, after moving to the heart of the grapefruit country in Florida, that he received the support needed to carry out his research.

Harich approached Dr Steven Otwell and Dr Wayne Marshall, both leading researchers, on the effects of microbes on food. Although initially sceptical, they were won over by the demonstration of GSE’s amazing ability to protect produce, fish, and poultry from the assault of bacteria, fungi, and parasites. The reputation of the two researchers coupled with the good reputation of the food science laboratory at the University of Florida, Gainesville, prompted other institutions to take Harich’s claims into consideration.

Finally, by 1990, holistic health practitioners in the United States began to hear about this remarkable product and its excellent results. Dr Harich’s efforts were finally given due recognition.

Nowadays, Grapefruit Seed Extract is the most widely used disinfectant and sanitizing agent in hospitals and clinics throughout the United States.

GSE: what is it?

GSE is an acronym that stands for Grapefruit Seed Extract. It is a standardized extract from grapefruit seeds and the white membranes covering the inner segments of the fruit. It can be either liquid or dry. The liquid solution contains 60% of grapefruit seeds and membranes extract and 40% of a watery solution of vegetable glycerine (obtained from coconut) with no additives, while the dry extract contains 50% of grapefruit seeds and membranes and 50% of inactive substances (natural excipients to facilitate manufacturing process).

In both cases, the extract is rich in polyphenolic compounds, including quercitin, helperidin, campherol glycoside, neohelperidin, naringin, apigenin, rutinoside, poncirin, etc. The polyphenols themselves are unstable, but are chemically converted into more stable substances belonging to a different category, namely quaternary ammonium compounds.

Some quaternary compounds, benzethonium chloride and benzalkonium chloride, for instance, are used industrially as antimicrobials, but are toxic to humans and animals. On the other hand, quaternary compounds such as B vitamin choline, called vitamin J, are not only safe but actually essential for maintaining healthy neurological functions and for the metabolism of fat.

GSE combines the best of both worlds: the quaternary compounds derived from grapefruit featuring broad-spectrum antimicrobial activity, yet without any of the toxic side-effects of chemically-derived quaternaries.

GSE: a powerful antimicrobial

Extensive testing carried out at laboratories and universities around the world has proven GSE to be effective against bacteria, viruses, fungi, yeast and parasites. What’s most surprising and unrivalled in the field is, beyond its efficacy, its speed of action.

The graph below shows the results of a study in which grapefruit seed extract and other antimicrobial substances were compared in their action against pathogenic microorganisms.  By the time GSE had completely inactivated the microorganism (100% bacteriostasis), iodine, chloric acid and silver oxide obtained only 10%, 5% or even less. In conclusion, the study demonstrated that GSE proves to be ten times more effective than the above mentioned substances against the microorganisms under examination.

GSE: antibacterial, antiviral, antifungal and parisiticidal

Antibacterial activity: according to published sources, GSE is effective against more than 800 bacterial strains (the table below features the most significant ones).

Furthermore, interest in GSE’s antibacterial power is growing due to problem of resistance to antibiotics that bacterial strains are increasingly developing. All this suggests that, owing to to its broad antimicrobial spectrum( Gram+ and Gram-), GSE might actually represent an effective alternative to conventional antibiotics. Allan Sachs, a certified clinical nutritionist, considers GSE an effective alternative remedy to antibiotic treatment because of its efficacy against fungus and bacteria, its safeness and selectivity (it does not significantly affect beneficial bacterial flora). On the contrary, according to Dr Sachs, many conventional antibiotics are, in fact, toxic, suppressing the normal functions of the immune system and destroying “friendly” bacteria. The powerful antibacterial activity of grapefruit seed extract is exploited for both internal and external use. In fact, GSE can be added to soaps and cleansing products as an antibacterial agent: its germ-killing action harms neither skin nor environment. Dr J.A. Botino, from the University of Sao Paulo in Brazil, tested GSE against alcohol and found GSE to be 100% effective for disinfecting skin before surgery, against 72% effectiveness of alcohol.

Antiviral activity: the results obtained on the efficacy of Grapefruit Seed Extract against viral strains sound promising. However, further research is needed to establish what the full potential of GSE is. In laboratory tests conducted by the Southern Research Institute and reported by William M. Shannon, Ph.D., head of the Microbiology-Virology Division, grapefruit seed extract was shown to be effective in inactivating HSV-1 (herpes simplex virus type 1) after a 10 minute exposure at a 1:256 dilution. Against human influenza virus type A2/Aichi/2/68 in vitro, the MIC (minimum inhibitory concentration) for GSE was the same, i.e. 1:256. The United States Dept. of Agriculture tested GSE and found it effective against four animal viruses: Foot and Mouth Disease, African Swine fever, Swine Vesicular Disease, as well as Avian influenza.  There is also evidence from several patients claiming that GSE dramatically lessened symptoms of even common cold and flu viruses. Besides direct action against certain viruses, GSE also exerts an indirect antiviral action thanks to its selectivity. In other words, GSE “cleans” the body from pathogens without destroying beneficial bacteria at the same time, thereby strengthening the physiological barrier effect and reducing workload of the immune system, which therefore maintains its efficiency and promptness in reacting to viral aggressions.

Antifungal activity: GSE is remarkably effective against more than 100 yeast and mould strains including Candida Albicans, responsible for recurring and relapsing infections of the mucous membranes and for systemic affections. Chronic candiasis can be successfully treated with GSE according to studies by Dr Leo Galland, New York, reporting 99% of success cases (treatment failure in only two out of 297 cases with no apparent development of side effects or drug resistance). In particular, vaginal Candida is very common in the western world and the relationship with systemic candidiasis has been largely demonstrated. The conventional approach based on synthetic antifungals does not offer satisfying results because of the development of drug resistance and because of the impoverishment of the bacterial flora, creating conditions for further relapses. In fact, destruction of beneficial bacteria at vaginal and intestinal level literally creates “physical spaces” for further development of pathogenic candidiasis, which in normal conditions is a harmless yeast-like fungus (saprophyte). Thanks to its effectiveness against this fungus and thanks to its selectiveness, GSE seems to be the best choice to fight  vaginal and systemic candidiasis.

Parasiticidal activity: efficacy of GSE against protozoan infections has been tested by the Food and Drug Administration. Dr Louis Parish used grapefruit seed extract to treat nearly 200 patients affected by Entamoeba histolytical and Giardia lambia. As a result, GSE gave symptomatic relief more than any other treatment. Furthermore, there is evidence on the efficacy of GSE against intestinal worms, especially common pinworms. The parasiticidal activity of GSE is also remarkable for external use: the extract has shown to be useful for fighting, overcoming and preventing head lice infestation.

GSE: antimicrobial action: how it works

It should come as no surprise that we know a lot more about what GSE is good for, than exactly how it actually works. This applies to many commonly used pharmaceuticals. A case in point is aspirin: since its development in 1899, billions of people have benefited from its anti-inflammatory, analgesic and antipyretic qualities. But exactly how it works has only recently been discovered.

From Seoul, Korea, Dr Sung-Hwan of Abcom Chemie Co., Ltd states: “As a result of our scientific studies,  we believe that microbial activity of GSE alters the cell membrane, thereby inhibiting its enzymatic activities.”

What remains unexplained is its antiviral action, given that viruses do not have a cell membrane of their own… while striking evidence shows it to be exceptionally effective.

Unravelling the mysteries of GSE and its mechanisms would undoubtedly provide extremely valuable insight into the basic activity of microbes. We hope that further studies will soon provide the answer to the many questions raised about how it can be so powerful and yet so safe.

GSE: amazing antimicrobial activity

Since Dr Harich’s discovery up until the present day, GSE has continued to surprise for its constant demonstration of efficacy against new strains of pathogenic microorganisms. Laboratories and Institutes all around the world and empirical evidence have shown that GSE is a truly broad- spectrum, natural antimicrobial agent.

GSE: cytoprotective and mucosa repairer

Recent studies conducted by a team of Polish researchers of the Jagiellonian University Medical College in Krakow have demonstrated further extraordinary properties of  Grapefruit Seed Extract. The research aimed to investigate the capacity of GSE to exert a protective action on the gastric mucosa, as assumed by preliminary studies. Results have been surprisingly positive: GSE’s cytoprotective action is proven by the increase in endogenous prostaglandin PG2 synthesis, the suppression of lipid peroxidation and the improvement of intramuscular blood flow mediated by the release of nitric oxide by sensory nerves. All this, together with the increase of the superoxide dismutase activity and the release of gastrin, promotes the repairing activity of the gastrointestinal mucosa.

This breakthrough, in addition to the well-known antibacterial properties of GSE against  Helicobacter pylori, enhances the functionality of GSE related to the gastroduodenal mucosa and makes it ideal for a natural and effective approach in restoring the functional and protective integrity of the mucosa. These results have confirmed the incredible cytoprotective role of GSE, highlighting its capacity to accelerate healing of lesions in the gastrointestinal mucosa.  GSE is therefore not only protective but also a repairer!

Moreover, the cytoprotective qualities of GSE have also been shown on tissues other than the gastrointestinal mucosa. In particular, the preventive role of the Grapefruit Seed Extract in inflammatory lesions of the pancreatic tissue has been investigated. In this case, too,  results of the study conducted by the Jagiellonian University Medical College in Krakow, have been surprisingly positive, showing a significant protective effect of GSE on the pancreas, mainly due to the inhibition of the oxidative stress and to improvement of the pancreatic blood flow.

GSE: unbelievable but true: it’s selective!

There is no doubt about the fact that antibiotics are one of the most important discoveries of modern medicine. It is thanks to antibiotics that millions of human lives have been saved. However, enthusiasm about this powerful weapon against bacteria has led many doctors to prescribe them all too easily, in other words to overuse them. The consequences of this have been, on the one hand, the development of antibiotic-resistant bacteria, and on the other the unpleasant side effects that can often outweigh the benefits.

For the few several years, even the World Health Organization has been warning medical authorities and healthcare professionals to limit prescriptions only to cases deemed necessary. Misuse of antibiotics over the years has led to a relentless rise of new bacterial strains that “have learnt” to resist these medicines, for which no treatment is yet available.

GSE represents a valid alternative treatment against many bacterial affections that do not require the use of antibiotics. This is not only due to its efficacy but also because of one particular feature that gives GSE the edge over antibiotics: its selectivity. Selectivity means that it distinguishes between pathogenic bacteria, considered enemies, and beneficial bacteria that make up the physiological bacterial flora. As inconceivable as this may seem, this is actually often the case in the natural world. For instance, antibiotics produced by Lactobacilli attack pathogens but not beneficial bacteria.

On the contrary, synthetic antibiotics and antifungals have a devastating impact on physiological flora. This produces very unpleasant effects in the medium and long term because even though appear to solve the problem at once, at the same time they create the conditions of a mechanism leading to chronicity: by killing physiological flora, all favourable conditions for a recolonization by pathogens are generated. Therefore, GSE is not only an alternative but the true remedy of choice for all affections that do not require antibiotics, especially when they are likely to trigger off recurring infections.

 “Selectivity” of GSE has been shown by a study published on the “Journal of Orthomolecular Medicine”, Volume 5, No. 3, 1990. After a four-week treatment with GSE, concentration of pathogens decreased considerably to normal values while the quantity of Lacto-bacilli and Bifidobacteria remained nearly the same. In short, GSE is effective against pathogenic bacteria without weakening the physiological bacterial flora.

GSE: safe!

Grapefruit Seed Extract is available in liquid and dry form and is therefore appropriate for both systemic and external use. The liquid extract is extremely bitter, though, and has a very low pH, meaning it is strongly acid. Therefore it should never be used pure and is recommended for external rather than internal use, especially concerning long-term systemic treatments, because it may cause irritation of the mucosa. For this reason, 2% concentration should not be exceeded. In any case, GSE already performs its best sanitizing effect at a concentration level of 1,5%.

As far as the dry extract is concerned, its pH is about 4,5 – 5 and it can be taken over a longer period without any trouble. The harmlessness of GSE has been largely demonstrated: its L.D. is greater than 5000 mg./kg of body weight. This means that an adult should swallow 4.000 times the recommended dose every day for two weeks in order to have 50% risk of fatal poisoning. GSE does not interact with medications, unlike grapefruit juice that may have this effect. Grapefruit juice exerts this effect by selective inhibition of cytochrome CYP3A4 in the gastrointestinal tract. Inhibition of CYP3A4 by a certain number of drugs (antibacterial, antidepressants, antifungals, antivirals and immunosupressants) is a well-known cause of interaction among drugs. In most cases, this ensues in an increased concentration of the bioavailability of the drug, that might become toxic with possible adverse effects. This is caused by naringin, which is dose dependent – meaning that in order to produce this effect, a concentration equal to the quantity contained in 200/250 ml of grapefruit juice is necessary. Naringin is also found in GSE, but in such small concentration that the daily recommended dose would have to be exceeded hundreds of times before causing inhibition of CYP3A4!

Safety of GSE for both humans and animals has been tested, endorsed and validated

by the F.D.A. (Food and Drug Administration) that has authorized its use in food and cosmetics as CRMS no. R0013982. Moreover, as a natural extractive, GSE is listed as GRAS (Generally Recognized as Safe) under the Code of Federal Regulations as 21 CFR 182.20.

It is important to know that at the beginning of treatment with GSE, a reaction known as “Herxheimer reaction” might occur. It generally manifests itself with symptoms like skin rashes, fatigue or momentary worsening of the symptoms that are evidence of the intense detoxification of the system. When viruses, bacteria, fungi and parasites are attacked by GSE, the body is overcharged by a big release of toxins. Few days up to some weeks are required to get rid of toxins. It is in this time lapse that the so-called “Herxheimer reaction” may occur. These side effects mean that the treatment is working and act as an indicator of the recovery process. In any case, in order to reduce these symptoms, especially in long-term treatments, it is advisable to start with a low dosage of GSE and to gradually increase it so as to avoid the simultaneous release of huge amounts of toxins. Furthermore, it is advisable to drink a lot of water with a low rate of total dissolved solids, which promotes the elimination of toxins.

GSE is safe because

  • its LD50 is 5000 mg/kg of body weight
  • GSE does not interfere with pharmaceuticals
  • GSE does not significantly harm beneficial intestinal flora

GSE: tested all over the world

GSE can be defined a “global” remedy because its properties allow endless applications and also because it has undergone testing at laboratories, clinics and universities all over the world, all of which have validated its effectiveness.

GSE: endless application possibilities

Endless application possibilities are offered by GSE thanks to its properties – effective antibacterial, antiviral, parasiticidal, antifungal, cytoprotective and mucosa repairer – and its flexibility of use (both dry and liquid extracts are conveyable through water and oil).

We believe that the best way to exploit such a powerful and broad-spectrum effective remedy is in association with other natural elements with specificity of action, rather than using it alone. The result is the creation of real “complete packs” with GSE as the main component in the proper dosage, aimed at to solving specific health problems. With this approach, different product lines have been created in order to provide effective treatment for a broad range of affections. Here follows a  list of the health diseases that can currently be treated using GSE-based supplements:

CANDIDIASIS (systemic, vaginal, oral, etc.)






INTESTINAL DISORDERS (constipation, diarrhoea, colitis, abdominal pain, etc.)


DIARRHEA (viral, bacterial, etc.)



GASTRIC DISORDERS (digestive disorders, infections by Helicobacter Pylori, etc.)


RESPIRATORY SYSTEM AFFECTIONS (cold, sinusitis, tracheitis, bronchitis, etc.)


CONJUNCTIVITIS (bacterial, viral, allergic, by chemical or physical agents, blepharitis, sty, etc.)


ACNE (spots, blackheads)

DERMATITIS (eczema, erythema, athlete’s foot, wounds, burns, etc.)

MYCOSIS (skin, nails, warts, etc.)



  • PEDICULOSIS (prevention and treatment)


At present, millions of people all over the world benefit from the extraordinary properties of Grapefruit Seed Extract. However, in some respects, it still remains a remedy for the “élite”. It would really be most remarkable if all humanity could profit from this precious natural gift: we hope that globalization – a term often associated with negative connotations – may help this dream come true.